Towns are marked in bold and market towns in italics: Býkev - Byšice - Čakovičky - Čečelice - Chlumín - Chorušice - Chvatěruby - Cítov - Dobřeň - Dolany nad Vltavou - Dolní Beřkovice - Dolní Zimoř - Dřínov - Hořín - Horní Počaply - Hostín - Hostín u Vojkovic - Jeviněves - Kadlín - Kanina - Kly - Kojetice - Kokořín - Kostelec nad Labem - Kozomín - Kralupy nad Vltavou - Ledčice - Lhotka - Liběchov - Libiš - Liblice - Lobeč - Lužec nad Vltavou - Malý Újezd - Medonosy - Mělnické Vtelno - Mělník - Mšeno - Nebužely - Nedomice - Nelahozeves - Neratovice - Nosálov - Nová Ves - Obříství - Olovnice - Ovčáry - Postřižín - Řepín - Spomyšl - Stránka - Střemy - Tišice - Tuhaň - Tupadly - Újezdec - Úžice - Velký Borek - Veltrusy - Vidim - Vojkovice - Vraňany - Všestudy - Všetaty - Vysoká - Zálezlice - Želízy - Zlončice - Zlosyň The landscape is mostly flat and belongs to the Polabí lowlands, only the northern part of the district is hilly and forested areas prevail.

The highest point of the district is the hill Vrátenská hora in Nosálov with an elevation of 507 m (1,663 ft), the lowest point is the river bed of the Elbe in Horní Počaply at 153 m (502 ft).

[1] The confluence of the two longest rivers in the country, Elbe and Vltava, is located in the centre of the district.

Kokořínsko – Máchův kraj is the only protected landscape area that extends into the district, into its northern part.

The largest employers with headquarters in Mělník District and at least 500 employees are:[5] The D8 motorway from Prague to Ústí nad Labem passes through the western part of the district.